Podcasting since 2005! Listen to Latest SolderSmoke

Sunday, January 2, 2011

A Blast from the Past: THE HAMMARLUND HQ-100

I'm sitting here in the shack at 0645 EST on the first Sunday morning in 2011. Coffee is on. And so is my OLD Hammarlund HQ-100. I have it tuned to a friendly AM roundtable on 75 meters. And it sounds GREAT. Nothing like a receiver that is as broad as a barn door to let you appreciate that great AM sound.

This receiver and I have some history. I bought it in the Dominican Republic, probably in 1993, probably from my friend (now SK) Pericles Perdomo. It had suffered the ravages of the Dominican radio environment from both ends: I think I found signs of a lightning surge at the front end, and of a power surge at the AC input. The audio output transformer was bad also. This was one of my first tube-type renovation project. I had a lot of fun with it.

There are no crystal filters in this receiver. If you want to narrow it down, there is a Q-multiplier (so --yikes!-- this receiver is at least in part a regen). In its original configuration the Q multiplier doubled at the BFO, but I guess my anti-regen feelings were at work even then: I took the 100 kc crystal calibrator and put a 453.5 kc crystal in there -- so that calibrator now serves as the BFO. This seems much more civilized.

You can see in the picture that the clock is gone. Mine was in pretty sad shape when I got it. Plus I thought it looked kind of goofy in that otherwise very beautiful front panel. So I took the clock out, patched the hole, and gave the clock to a very grateful Hammarlund collector.

The AM really sounds great. I can see that I'm going to need a 75 meter dipole so I can match this receiver up with my DX-60 VF-1 combo.

Saturday, January 1, 2011

If You Could SEE The Night Sky at Radio Frequencies

Image courtesy of NRAO/AUI

SolderSmoke is mainly about radio, but we make frequent detours into astronomy. The picture above nicely combines the two fields. This is what the night sky would look like if our eyes received at radio frequencies! Here's how the National Radio Astronomy Observatory describes their image:

This composite picture shows the radio sky above an optical photograph of the NRAO site in Green Bank, WV. The former 300 Foot Telescope (the large dish standing between the three 85 foot interferometer telescopes and the 140 Foot Telescope) made the 4.85 GHz radio image, which is about 45 degrees wide. Increasing radio brightness is indicated by lighter shades to indicate how the sky would appear to someone with a "radio eye" 300 feet in diameter. The optical and radio skies reveal "parallel universes" containing quite different objects. The extended radio sources concentrated in a band from the lower left to upper right lie in the outer Milky Way. The brightest irregular sources are clouds of hydrogen ionized by luminous stars. Such stars quickly exhaust their nuclear fuel, collapse, and explode as supernovae, whose remnants appear as faint radio rings. Unlike the nearby (less than 1000 light years distant) stars visible to the human eye, almost none of the myriad radio "stars" scattered over the sky are really stars at all. Most are luminous radio galaxies or quasars, and their average distance is over 5,000,000,000 light-years. Radio waves travel at the speed of light, so distant extragalactic sources appear today as they actually were billions of years ago. Radio galaxies and quasars are beacons of information about galaxies and their environs, everywhere in the observable universe, ever since galaxies first formed. Investigator(s): J. J. Condon, J. J. Broderick, and G. A. Seielstad

Higher definition images and lots more info is available here:
http://images.nrao.edu/Miscellaneous/Surveys/321 Three cheers for the NRAO!

So... Think BIG in 2011! Happy New Year and 73 to all!

Friday, December 31, 2010

Storm on Saturn (with radio waves)

There is a big and very unusual storm on Saturn right now. You can see it in the image above. It was taken by amateur astronomer Jim Phillips using an eight inch telescope. I've been out before dawn for the last two mornings trying to see the storm with my 6 inch Dobsonian reflector telescope. I get very nice views of Saturn and Titan, but I can't quite make out the storm. Conditions have not been great, and I'm not sure the storm was in view when I was looking.

The folks at spaceweather.com note that it is generating some static:

Instruments on NASA's Cassini spacecraft are picking up strong bursts of radio static. Apparently, lightning is being generated in multiple cells across the storm front.

Space weather indeed!

Thursday, December 30, 2010

Our New SolderGlobe >>>>>>>>>>>>>

I really like this little globe. The red dots record past visits. But the fun part is the flags and city names that pop up showing who is currently looking at the site. Very nice.

You can make the globe spin faster (or backwards) and you can tilt the axis of rotation up and down with your mouse. Give it a spin!

Wednesday, December 29, 2010

Halogen Lamps and Heat Guns to The Rescue!

Hi Bill,

Your recent success with baking your Sony Vaio gave me the courage to attack my flat screen monitor. The most expensive thing in my entire computer setup is my "LG" brand monitor. It's the only thing that I've purchased new. Everything else came from the curb, or the surplus store. However, it started going on the fritz a few weeks ago.

While browsing around the chat groups on the internet I found out that many monitors from the past few years have had bad capacitors in them. So I opened it up, hoping to find a blob of leaking chemicals near a cap. "It should be a quick fix" I thought. However, everything looked great. No bulging caps, or leaking chemicals. I then turned the circuit board over, and instead of seeing a shining city of perfect solder joints, I saw a cloud of grey. Practically every solder joint was cold.

This is where your laptop baking got me thinking.

I didn't have a halogen lamp handy, but I did have a heat gun. So I put the gun on the high setting, and very slowly passed it over the board. It left a gleaming trail of solder joints.

When I started to connect things back together again, I heard a rattling. It seems that I heated the board up enough to allow some components to completely fall out. Luckily they were through-hole components (nothing surface mount), and were easy to solder back in.

Once everything went back together... success!

One thing to note, at one point I got a nasty zap from one of the caps on the board (I'm assuming for the back light). Even though we're not working with tubes and CRTs anymore, you still have to take heed and discharge high voltage caps before working on anything!

-Keith VE3TZF

Tuesday, December 28, 2010

Blue Light in Dark Ice

Down in Antarctica, the "Ice Cube" neutrino telescope was completed this month. It is an amazing piece of gear in an awesome location. Essentially, they use a 1 kilometer square piece of pure Antarctic ice as the detector -- when a neutrino hits a water molecule, it makes a bit of blue light and from this light the direction of the neutrino can be determined. But there is a problem: cosmic rays can create the same kind of blue light. So there's noise. They need a filter, right? Yes, and for this purpose they use... THE EARTH. They put the blue light detector at the TOP of the cube and look DOWN, down through the Earth! Only neutrinos get through.

For more details: http://www.icecube.wisc.edu/info/explained.php

Friday, December 24, 2010

R/C Plane with Camera over New York City


This is really amazing. You should watch it in HD. 120 mile range? Maybe from the top of the Empire State building, right?

More info here:

http://singularityhub.com/2010/12/21/breath-taking-aerial-video-footage-from-new-york-city-taken-by-a-rc-plane/

Thursday, December 23, 2010

DXers: What is my path to VK6XT?

I've been looking with pride at the WSPR map (below) showing that my little beacon has been received by far-off VK6XT. He picked me up again this morning, again only once. That makes three days in a row, each day only one report. Each time VK6XT is the only station in the Oceania area receiving me. And each day the my signal makes the trip around 1025 UTC. Now, I'm not a skilled DX'er, but it seems obvious to me that we are dealing with grey-line propagation here, right?

The image above shows the view from the sun at 1025 UTC today. Obviously the day/night terminator is along the perimeter of the earth in this image. So, I guess my little sigs could have been travelling either short path over Northern Europe and down over South East Asia OR they could have taken the long trip down over South America, over Antarctica, and on to Perth. My guess is that the short path is more likely. In any case, as cool as it is, the map drawn by the WSPR system is not how the sigs actually travelled.


I hope you DX hounds out there will chime in and tell me if I'm on the wrong path here...

Wednesday, December 22, 2010

The Payoff from WSPR

TimestampCallMHzSNR
GridPwrReporterRGridkmaz
2010-12-22 09:28 N2CQR 10.140215 -28
FM18jv 0.2 VK6XT OF86td 18576 288
2010-12-21 10:28 N2CQR 10.140221 -28
FM18jv 0.2 VK6XT OF86td 18576 288

I know some of you guys consider WSPR kind of weird, kind of narcissistic, more like broadcasting than real amateur radio. I hear you. As creator Joe Taylor himself has pointed out, these are not really QSOs. But I have to tell you, it is very satisfying to walk into the shack, and, with coffee cup in hand check the WSPRnet screen to see who has recently received your little QRPp signal.
For the last two mornings, I've found VK6XT receiving mine. That's 18,576 kilometers covered by 200 milliwatts to a low dipole. In Western Australia my signal is 28 db below the noise (that means below the noise in a standard SSB passband). I see that I'm making the trip only once each day, at around the same time, and that VK6XT is the only Oz station picking me up. Very cool.

Here is Richard, VK6XT, the fellow at the other end of the path:

I was born in Christchurch, New Zealand in December 1954. Keen on shortwave as a boy, I went to Rangiora High School and met Gary Watson ZL3SV who sparked a lifelong interest in Ham radio. However Life intervened and it wasn't until 1976 in Wollongong, Australia that I first transmitted as VK2NNL.(after a brief fling on The illegal CB band). I upgraded and then returned to NZ to become ZL1OK from Rotorua. I became a DX hound and worked 256 countries for DXCC. The high point of my DX activities was in 1991 when I organised a DX-pedition to the Auckland islands. We operated as ZL9DX / ZL9YL and Kerry operated ZL9TPYon 6 metres. Always keen on home brewing and QRP gear I now work in Perth as a Design and Technology Technician. My ham radio activity is at present operating an Icom IC7400 to a variety of antennas 160m to 2m. . I am keen on the digital modes, especially PSK31, and spend my spare time on my hobby farm near Katanning(300 kM south of Perth).

Tuesday, December 21, 2010

Ham Radio Time Capsule at University of Virginia

Bert, WF7I has been sending us some great info from the University of Virginia's radio club. Listeners will recall his adventures in putting up and taking down the rhombic antenna. This week Bert sent in excerpts from his research on the history of the UVA club. This bit came from Lee, KD4RE. I know there are a number of "anchor-ologists" out there (fans of the Boatanchors i.e. big, old tube radios). I thought you guys would get a kick out of this. Oh, wouldn't you want to find a room like this one?

Back in 1971 a student named
Bill Hughes was Ham and knew I was a ham
and he wanted to get the UVA Ham radio club started up again. There
were a couple of other Hams around, Dave Wolfe who was Chief Engineer
at WTJU before me, has a 2-B receiver in the engineering (transmitter
room) at WTJU when in was in the basement of Humphreys.
(Yeah I have a lot of WTJU Stories..).. Anyway Bill told me he heard
that the last active ham radio club had been located over in one of
the ground rooms behind Varsity Hall (which has since been moved to
make room for Rouse Hall expansion) In those days it was the Air Force ROTC building. Anyway, the ground level had a brick floor and sort of an open portico and across the back were a bunch of rooms (all brick of course). well we came to the old door and saw open wire feeder remnants overhead We opened the door and it was like opening a time capsule - There in the room was mostly 1930s and 1940s vintage gear, I guess it had not been used since the mid 1950s (or early 1950s).

There was a rack with an AM transmitter in it, sort of a copper
colored paint on the front and on it was a piece of cardboard with the call sign W3VA. There were a number of old receivers in the
room I recall a National HRO with its plug-in coils there was and RME
receiver with a tunable preamplifier/selector as a separate box, and
several others. I am not sure but the DX 100 we had for a while may
have come out of there so that would have been late 1950s then...

For more UVA Radio Club history go to:
http://www.student.virginia.edu/~w4uva/file-storage/history/index.html

Save 15% on "SolderSmoke -- The Book" TODAY

Use coupon code: DEC21
http://soldersmoke.com/book.htm
Designer: Douglas Bowman | Dimodifikasi oleh Abdul Munir Original Posting Rounders 3 Column